The coloration of human skin is determined principally by the concentration of melanin produced by the melanocytes. The melanocytes are specialized cells, which synthesize melanin by means of specific organelles, the melanosomes. The same holds true for the coloration of hair on the head and body, as well as the fingernails and toenails. Medical disorders which cause a loss of these melanocytes can result in diseases, such as vitiligo, marked by a loss of skin pigmentation.
Vitiligo affects 1%-2% of the world population, and results from a lack of melanin in the epidermis due to the disappearance of melanocytes from the skin. Clinically, the patients display white areas of various sizes and shapes, either localized or generalized. Frequently, these white areas have a symmetrical distribution on both halves of the body. Vitiligo can begin at any age and become gradually progressive to the point of affecting the entire skin. Although the precise cause of vitiligo is not known, such clinical behavior speaks in favor on an internal or systemic etiology. It is possible that vitiligo is an autoimmune condition. Studies have reported that patients with vitiligo exhibit a circulating autoantibody that binds to melanocytes in human skin, nevus cells and melanoma cells.
Despite extensive therapeutic efforts over the years, the treatments available are unsatisfactory, to say the least. W. B. Shelley, the great master of American Dermatology, has summarized the drama and frustration in the management of this disease, particularly in the darker skin, as follows: “the vitiliginous areas of the face are truly disfiguring. Years ago Nehru recognized this fact by ranking the need for a treatment of vitiligo on a level with that for leprosy and tuberculosis. In all instances there is a quest for help. At present the best we can offer is little. Surely in this century of moon flights, we should be able to do better . . . ” (W. B. Shelley, “Consultations in Dermatology”, W. B. Saunders, Philadelphia, 1972).
Various solutions have been proposed to the art of artificial coloration by applying dyes that are intended to color the skin and or hair to match as close as possible its natural color or in the field of natural coloration via stimulation of the natural pigmentation pathways or in the field of decoloration by depigmenting the skin. Good results have been obtained with some negative side effects. A number of methods of treating skin depigmentation are available; while some are effective to a greater or lesser degree, most have some drawbacks. One such method involves the use of pseudocatalese cream (PCAT), which should be applied twice daily. PCAT contains calcium chloride, manganese chloride, sodium bicarbonate, and distilled water. PCAT inhibits the progression of pigment loss, and reduces skin levels of peroxides which are known to be increased in vitiligo patients. However, there are certain drawbacks to PCAT. First, the cream can cause skin to break out in pimples and cause ingrown hairs. Also, patients should be screened for phenylalanine deficiency first as PCAT is more effective for people with phenylalanine deficiency.
Novitil, which works as a tanning accelerator, has also been tried as a vitiligo treatment. This is a formulated gel containing oils, distilled water, glycerin, carboxmethylcellulose, camphor, menthol, polypeptides, Aloe Barbadensis, oligoelements and kathon (a preservative), which is used in conjunction with exposure to the sun or a sun lamp for it to work. Sinvitil, an earlier version of Novital which did not include the polypeptides, Aloe Barbadensis, and oligoelements, has also shown promise in repigmentation therapy. However, these gels must be left on for at least two hours after treatment, significantly restricting the patient's mobility.
Another topical treatment is V-Tar, a 30% standardized water soluble coal tar product which also contains natural anti-inflammatory agents, skin conditioners, and antioxidants. V-Tar has been used successfully in many patients with vitiligo and other hypopigmentary disorders. It will not stain the skin, and its once weekly application is convenient for many patients. V-Tar is available only with a physician's prescription.
Other topical treatments include the use of steroid creams or immunomodulators. Application of steroid creams to white patches of vitiliginous skin for three months can aid in skin repigmentation; however, this treatment can cause thinning of the skin, blood vessel formation, steroid induced acne, atrophy, joint problems, and possibly arthritis. In theory, topical immunomodulators alter the immune response to the skin, curbing the immune response in vitiliginous skin. The ointment Protopic is such an immunomodulator. Those who have tried protopic report burning and itching as side effects. Although Protopic has been approved by the FDA for eczema, the FDA does not support the clinical investigation or use of Protopic for vitiligo at this time.
PUVA, a phototherapy treatment involving use of psoralen, in conjunction with ultra violet A (UVA) light is another common treatment. In one frequently-used regimen, oral doses of psoralen are taken two hours before exposure to UVA light or to sun light. Normally, the patient wears wraparound sunglasses to protect his or her eyes. Alternatively, topical psoralen therapy, in which psoralen is applied to skin 30 minutes before exposure to UVA light until white, vitiliginous skin turns pink, may be used. These treatments, however, have significant side effects, including sunburn, redness, blistering, and inflammation. PUVA treatments are not recommended for children under age 10 because phototherapy can cause eye damage and cataracts. Oral psoralen can also cause severe stomach upset, gastrointestinal upset, nausea, and liver toxicity. Phototherapy with psoralen has also been linked to some forms of cancer, including nonmelanoma skin cancer. In the case of oral psoralen, the patient must avoid sunlight for 12-24 hours after treatment. The patient must wear special sunglasses for two hours following treatment. Maintenance treatments are required to see continued improvement.
Narrow band UVB or excimer laser treatment of vitiliginous skin consists of highly concentrated beams of narrow band UV light. This procedure maximizes delivery of narrow band UVB radiation to the tissue requiring treatment, while minimizing exposure to superfluous UV radiation. However, this form of phototherapy can also cause burning, like PUVA. This sunburn is less severe than other forms of UV light, but it is not safe around the eyes. Some patients have, however, reported significant success.
In particularly severe cases of vitiligo, where the patches of white skin cover large parts of the body surface, depigmentation is sometimes used. In this therapy, the drug monobenzylether of hydroquinone (monobenzone or Benoquin) is applied to skin twice a day until pigmented skin fades skin fades until it matches the patches of depigmented skin. The patient must avoid skin to skin contact with other people for at least 2 hours after application of the drug. Some patients have allergies to Benoquin, and show contact dermatitis, including inflammation (redness and swelling), rash, itching, and dry skin. The rash, inflammation, and itching have been likened to poison ivy. Depigmentation once completed, leaves the patient extremely sensitive to sunlight. This treatment is, in most cases, permanent.
If desired by the patient, surgical procedures may be explored. These include skin grafting and melanocyte transplant. In skin grafting, pieces of normal skin are removed and placed in white skin patches. Melanocyte transplant involves placement of a sample of normally pigmented skin in a laboratory dish with a solution to grow melanocytes. After the melanocytes have multiplied, they are transplanted into the depigmented skin or depigmented skin of the depigmented hair. Both of these procedures are invasive, and may result in infections, scarring, and/or uneven skin pigmentation.
For patients who prefer to avoid medical or surgical intervention, the condition may be concealed with cosmetics for the skin or dye for the hair. However, these cosmetic treatments do not solve the problem, and need continuous application. Some cosmetics may cause allergic reactions.
Nutritional repigmentation therapies using vitamins and/or minerals known in the art to be safe have been proposed. One such nutritional therapy for vitiligo was described by Montes (U.S. Pat. No. 4,985,443). This therapy involves oral treatment with folic acid, alone or in combination with vitamins C and B12. A second repigmentation therapy, disclosed as useful for treatment of grey hair, but not vitiligo, was proposed by Nelson (U.S. Pat. No. 6,149,933). This treatment regimen involves administration of copper, p-aminobenzoic acid, pantothenic acid, and vitamin B6.
The Nelson and Montes treatments have achieved some good yet inconsistent results. One area their treatments overlook is vitamin and mineral absorption. Some of their test patients did not achieve any results or unsatisfactory results. It is possible that these patients did not absorb (in their digestive systems) the vitamins and minerals.